This invention relates to a method for producing a cellular molded article having a surface skin in a mold pattern which is used, for example, as an automobile interior trim material or the like and an article thereof
As for the conventional technique of this kind, for example, (a) so-called simultaneous molding with a surface skin in once (simultaneous one piece molding) is known as disclosed in TOKUKAI-SHO 62-108039. In this method, as illustrated in FIG. 26, a male-female coupled mold pattern 2 is used, and after a surface skin material 3 is preformed by vacuum-forming along a cavity surface 2a of female pattern 9, an expansion molding is performed in a cavity (inside of the mold pattern) 4 which is shaped up by a male pattern 10 combining with a surface skin material 3, at the same time, a cellular molded article (a cellular molded article in a mold pattern) 5 is united with the above-mentioned surface skin material 3 simultaneously. In this simultaneous molding, when the above-mentioned surface skin material 3 is vacuum formed, the outer edge part of said surface skin material 3 is fold-back formed as well from opening edge 2b toward an inside direction of the mold pattern along a folded back pattern (pattern for folding back) 6 which projects from opening edge 2b of the above-mentioned cavity face 2a toward the inside direction of the mold pattern in advance, and when the above-mentioned expansion molding is performed, a folded back part 7 of surface skin material 3 is united into one piece with back face 5b of the above-mentioned expanded molded article (the expanded molded article in the mold pattern) 5.
In this method, at a time of the above-mentioned vacuum forming, the outer edge part of the surface skin material 3 is formed in advance as folded back from tip 7c of the folded back part 7 toward outside direction of the mold pattern in a manner of rolling up folding pattern (pattern for folding back) 6, an expansion molding is performed with this state. And, after obtained a cellular molded article having a surface skin material (a cellular molded article having a surface skin in a mold pattern) 71a is removed from the pattern, unnecessary outer edge part of the surface skin material 3 is trimmed off at tip 7c of the above-mentioned folded back part 7.
(b) On the other hand, it is known that, in a cellular molded article having a surface skin in a mold pattern with a surface skin in which an insert member is melt united with outer edge part of back face 5b of cellular molded article 5, when the outer edge part of surface skin material 3 is folded back to back face 5b side of cellular molded article in a mold pattern 5, a prescribed range of the outer edge part of surface skin material 3 is cut off so as to avert the above-mentioned insert member, thereafter, it is necessary a process of folded back part 7 to be adhered to back face 5b of cellular molded article in a mold pattern 5.
(c) Furthermore, in a simultaneous one piece molding as in the above, a chamber connected with steam valve, decompression valve or the like is equipped in each of the 2 metal mold parts. And one metal mold part of them on which a surface skin material will be placed is formed to have a plural of decompressing holes and the other metal mold part is formed to have a plural of vapor holes connected with the above-mentioned chamber respectively. And when an expansion molding is performed, the filled expanded beads in this mold pattern are heat-expanded by feeding of a steam from the vapor holes of the above-mentioned the other metal pattern part to inside of the mold pattern.
In this case, for a purpose of effective expansion molding by preheating of the above-mentioned surface skin material to be preformed, it is common that the above-mentioned one metal pattern part is preheated by feeding of a steam into inside of the above-mentioned chamber before this surface skin material is placed on.
Nevertheless, in the above-mentioned (a) conventional example, since the outer edge part of the above-mentioned surface skin material 3 is at a state of standing from tip 7c of the above-mentioned folding back part 7 at a prescribed angle against back face 5b of cellular molded article (cellular molded article in a mold pattern) 5, when the above-mentioned outer edge part is trimmed off at tip 7c of folding back part 7, a prescribed length of projected edge part may remain. In such a case, when transportation, assembling process or the like of the cellular molded article having a surface skin material (cellular molded article having a surface skin in a mold pattern) is conducted, since the above-mentioned projected edge part may often hang up with the other member materials, there is a problem of easily peeled from tip 7c of the above-mentioned folded back part 7.
And also, in the above-mentioned (b) conventional example, since the trim process and the adhesion process for a prescribed range of folded back part 7, which is necessary when an insert member material is melt united to one piece, are needed all by hand works, there is a problem of requiring much labor.
Moreover, in the above-mentioned (c) conventional example, when the above-mentioned one metal pattern part is preheated, since the metal pattern part is totally heated by feeding a steam into the inside of its chamber, there is a problem of insufficient heating efficiency. In furthermore, when the above-mentioned surface skin material is place on by a vacuum forming, even though the above-mentioned one metal pattern part has been preheated by steam, at a time of decompression, since the heat is taken away by a vaporizing heat of condensed moisture within the chamber, there is a problem of lowering temperature of the metal pattern part, by which an efficient vacuum forming will not be successful. And furthermore, when the metal pattern part is preheated directly by steam, moisture or water drop will remain on the surface of metal pattern part, consequently, since this water drops or the like are stuck on surface of the skin material, there is a problem that surface appearance of the surface skin material is deteriorated, at the same time, when the surface skin material is placed on the one metal pattern part by a heat-molding such as vacuum forming, there is a problem of lowering its elongation property at a time of heat-molding.
This invention has been done for solving the above-mentioned problems,
(1) the folded back part, which is folded back to backside face of a cellular molded article in mold a pattern and melt united to one piece, is hardly peeled off,
(2) less hand working even when an insert member material is assembled,
(3) an expansion molding or a heat-molding of the surface skin material can be done effectively,
(4) improving the surface property of the surface skin material and/or the elongation property at a heat-molding,
(5) good heat efficiency of the metal pattern part at a time of preheating on which the surface skin material is placed,
it is objecting to provide a method for producing a cellular molded article having a surface skin in a mold pattern and a molded article thereof.
An essential feature residing in a method for producing a cellular molded article having a surface skin in a mold pattern of this invention which is claimed is that, in a method for producing a cellular molded article having a surface skin in a mold pattern in which the above-mentioned surface skin material is melt united to one piece with the surface of the cellular molded article in the mold pattern which is molded by an expansion molding within this mold pattern, after the surface skin material is heat-molded along a cavity face of the mold pattern, it is characterized in that when the above-mentioned heat-molding, after the outer edge part of the above-mentioned surface skin material is folded back toward the inside direction of the mold pattern and formed a folded back part along the pattern for folding back which is arranged so as opening the edge of the above-mentioned cavity face to project toward the inside direction of the mold pattern, and then, the above-mentioned pattern for the folding back is removed, thereafter, at a time of the above-mentioned expansion molding, the one face of the above-mentioned folded back part is melt united to one piece with the back face of the cellular molded article in the mold pattern as well as the folded returning part, which is in a state that the outer edge part of the surface skin material is folded back toward an outside direction of the mold pattern from the tip of this folded back part, is pressed so as to pile on the other face of the above-mentioned folded back part. Accordingly, a cellular molded article having a surface skin in a mold pattern can be produced in one serial process by using the above-mentioned mold pattern, and therefore, there is an advantage of that the assembling process for folding back the surface skin material to the back face of the above-mentioned cellular molded article in the mold pattern is unnecessary. Furthermore, by applying the above-mentioned whole process, there is another advantage of that, by pressing the above-mentioned folded returning part so as to be piled on the other face of the folded back part, the above-mentioned folded back part can be easily molded so as to be in a state of simply piled or melt adhered to one piece, in other words, so as to be in a state of approximately parallel position against the back face of the above-mentioned cellular molded article in the mold pattern. Moreover, in order to protect the surface side appearance of the cellular molded article having the surface skin in the mold pattern, the outer edge part of the above-mentioned surface skin material may be trimmed off simply by making the tip of the folded returning part to be positioned at the inside direction of the mold pattern from the base edge of the folded back part. Therefore this trimming work is advantageously to be done easily and is not necessarily to take care much for it.
An essential feature residing in what we claim is that, at a time of heat-molding, the above-mentioned folded returning part is pre-formed beforehand to a state that it is folded back to the outside direction of the mold pattern as in a manner to be rolling up the pattern for folding back from the tip of the above-mentioned folded back part. Accordingly, only by clamping the above-mentioned mold pattern parts completely, the above-mentioned folded returning part can easily be pressed so as to be piled on the other face or the like of the folded back part. Therefore, when the above-mentioned expanded beads are filled into the mold pattern, hand-work of that, the outer edge part of the surface skin material which will become to be the folded returning part is folded as returning from the tip of the folded back part to the outside direction of the mold pattern, can advantageously be omitted.
An essential feature residing in what we claim is that the outer part of the above-mentioned surface skin material is trimmed off beforehand so as the tip of the folded returning part to be positioning inside of the mold pattern from the base edge of the folded back part. Accordingly, after production of a cellular molded article having a surface skin in a mold pattern, the trimming work of unnecessary outer edge part of the surface skin material is omitted, and also, the above-mentioned folded returning part is made to be melt united to one piece with the other face of the folded back part so that this folded back part will not be peeled out. These are also advantages.
An essential feature residing in what we claim is that an angle between the cavity face and the pattern for folding back at the above-mentioned opening edge is set up larger beforehand than an angle between the back face and an edge of the surface of the above-mentioned cellular molded article in the mold pattern. Accordingly, at a time of heat-molding such as the above-mentioned vacuum forming, an angle between the folded back part of the surface skin material and the surface part at the above-mentioned opening edge can be made larger than that of afore-mentioned conventional case. By this reason, when the expanded beads are filled into the above-mentioned mold pattern, the expanded beads are more easily filled to the outer corner part of back face of the above-mentioned cellular molded article in the mold pattern as well, consequently, the expansion molding of a cellular molded article in a mold pattern advantageously can be done more uniformly.
An essential feature residing in what we claim is that, at a time of the above-mentioned expansion molding, an insert member is connected with at least either one of the above-mentioned folded back part or folded returning part. Accordingly, there is an advantage in that the trimming process of folded back part by hand-work and the adhesion process which are used in the conventional process are not necessary and thus hand-working is lessened. Furthermore, even when these folded back part and folded returning part are formed, a connecting position of the insert member is not limited to a specified position but advantageously is enabling to connect with various position in a vicinity of the outer edge part on the back face of the above-mentioned cellular molded article in the mold pattern.
An essential feature residing in what we claim is that, before the above-mentioned heat molding is done, a cut off part for setting up the insert member at the tip of the above-mentioned pattern for folding back is prepared beforehand. Accordingly, the folded back part or the like can be formed with a prescribed space being prepared at the inside direction of this cut off part for setting up the insert member. Namely, when the insert member is connected with backside of the cellular molded article in a mold pattern, the folding back of the surface skin material or the like can be done automatically in a manner of averting this insert member, and thus there is an advantage of lessening the hand-work.
In further, an essential feature residing in what we claim is that it comprises a cellular molded article in a mold pattern and a surface skin material which is comprising in that a surface part which is melt united to one piece with the surface of the said cellular molded article in the mold pattern, a folded back part in which the edge part of said surface part is folded back toward the inside direction of the mold pattern and of which one face is melt united to one piece with the backside of the above-mentioned cellular molded article in the mold pattern, and a folded returning part which is folded returning so as to pile on the other face of this folded back part from the tip of said folded back part to the outside direction of the mold pattern and at the same time so as its tip to be positioning in the inside direction of the mold pattern from the base edge of the folded back part. Accordingly, when said cellular molded article having the surface skin is transported or assembling processed, the tip of the above-mentioned folded back part and folded returning part are hardly hung on the other member material or the like and thus it is advantageous that the above-mentioned folded back part is hardly peeling out. And also, in the above-mentioned piled part of folded back part with the folded returning part, there is an advantage of that a cushioning property and/or reinforcing effect can be raised.
An essential feature residing in what we claim is that the above-mentioned folded returning part is melt united to one piece with the other face of the folded back part. Accordingly, the folded returning part is hardly peeling out, which is also advantageous.
An essential feature residing in what we claim is that an insert member is united with at least either the above-mentioned folded back part or folded returning part. Accordingly, the strength of united part of this insert member with the above-mentioned folded back part or folded returning part is advantageously more increased.
An essential feature residing in what we claim is that the above-mentioned folded back part and folded returning part are folded back and folded returning in a manner to avert the insert member which is melt united to one piece with backside of the above-mentioned cellular molded article in the mold pattern. Accordingly, the above-mentioned insert member can be melt united as well in a manner that is buried in the back face of said cellular molded article in the mold pattern, which is advantageous in that an assembling variation for the insert member can advantageously be broadened.
An essential feature residing in what we claim is that the above-mentioned surface skin material and cellular molded article in the mold pattern consist of polyolefine resin. Accordingly, a melt uniting of such surface skin material with the cellular molded article is hard, at the same time, there is an advantage in that recycling of it is easy since it is so-called all polyolefine.
An essential feature residing in what we claim is that the above-mentioned surface skin material, the cellular molded article in the mold pattern and the insert member consist of a polyolefine resin, accordingly, in addition to the above-mentioned what we claim, the melt uniting of the surface skin material or the cellular molded article in the mold pattern with the insert member is more hard, and in further, recycling is easy as well, which is also advantageous.
In addition to these, an essential feature residing in what we claim is that, in a method for producing a cellular molded article having a surface skin in a mold pattern by a method which the cellular molded article in the mold pattern to be formed with filling of the expanded beads and the above-mentioned surface skin material are melt united to one piece by an expansion molding within this mold pattern after the surface skin material is placed on either one of the two metal mold parts which are composing a mold pattern, to a part of the above-mentioned one metal mold part which at least is composing an exposure face to the inside direction of the above-mentioned mold pattern, a heater which will enable to keep this exposure face at a prescribed temperature is assembled. By this method, the above-mentioned exposure face is pre-heated at a prescribed temperature before the above-mentioned expansion molding. And at the same time, said preheating is done by steam of lower temperature than that of the above-mentioned expanded beads to be melt-uniting each other, and after the steaming for keeping this state for a prescribed period, by a vacuuming of the inside of the above-mentioned mold pattern, the condensate residing inside of it is evacuated.
Accordingly, the surface skin material being placed on this exposure face is also pre-heated up to a prescribed temperature. Consequently, the expansion molding, namely, the melt uniting of the surface skin material with the expanded beads which make expansion within the mold pattern can be effectively done, which is an advantage as well. Also, as heating only for the above-mentioned exposure face is possible, the heat effectiveness is superior. Moreover, since the moisture or water drops will not remain on this exposure face when preheating of the above-mentioned exposure face is taken place, the surface appearance of the surface skin material can be improved, and at the same time, when the surface skin material is placed on one of the metal mold patterns by a heat-molding, the elongation property at its heat-molding is also advantageously improved. In addition, by means of preheating of said expanded beads by steam, steaming thereof and evacuation of the condensate as described above, an insufficient melt uniting of said expanded beads by themselves and an insufficient melt uniting of said expanded beads with the surface skin material will not be caused, and at the same time, by a preheating of the cavity face by a heater, the condensate can easily be evacuated. Thus these are also advantages.
An essential feature residing in what we claim is that the above-mentioned surface skin material and cellular molded article consist of polyolefine resins. Accordingly, melt uniting of these surface skin materials with the cellular molded article can be made tighter, and also, the obtainable cellular molded article having a surface skin in a mold pattern is so-called xe2x80x9call olefinxe2x80x9d, by which recycling is advantageously easy as well.
An essential feature residing in what we claim is that the temperature of the exposure face before the above-mentioned expansion molding is set up at in a range from 60 to 150xc2x0 C. Accordingly, the surface skin material placed on this exposure face is becoming appropriately softened, and by this reason, a melt uniting of the surface skin material with the expanded beads can be more effectively done, which is advantageous as well.
An essential feature residing in what we claim is that the above-mentioned surface skin material is placed on one of the above-mentioned metal mold parts by a heat-molding. Accordingly, the hand-works for pre-adjusting to the surface formation of the above-mentioned one metal mold part by the other molding process beforehand or the like can be advantageously omitted.
An essential feature residing in what we claim is that the above-mentioned exposure face is pre-heated up to a prescribed temperature before the above-mentioned heat-molding. Accordingly, a temperature lowering of the softened surface skin material to be tightly contacted with this exposure face can be minimized, and by this method, a heat-molding such as vacuum forming can be effectively done, which is also advantageous as well.
An essential feature residing in what we claim is that the above-mentioned temperature of exposure face before the above-mentioned heat-molding is set up at in a range from 60 to 150xc2x0 C. Accordingly, when the above-mentioned surface skin material and cellular molded article are composed of a polyolefine line resin, the above-mentioned surface skin material can be heat-molded at an appropriate softened state, consequently, the final property of product can advantageously be improved as well.
An essential feature residing in what we claim is that at least a part which is composing of the above-mentioned exposure face consists of a gas permeable electric cast mold, a gas permeable metal mold or a gas permeable ceramic mold. Accordingly, when the above-mentioned surface skin material is placed on by a vacuum forming, the air and gas residing between said gas permeable electric cast mold or the like and said surface skin material can more easily be evacuated. By this reason, there is an advantage that the above-mentioned surface skin material can more surely be contacted with said exposure face, and at the same time, since the diameter of said gas permeable holes is very fine, marks of these gas permeable holes will not be printed on the surface of the above-mentioned surface skin material.
An essential feature residing in what we claim is that an unevenness for product design pattern is pre-formed on the above-mentioned exposure face beforehand. Accordingly, there is an advantage of that when said surface skin material is placed on by a heat molding such as a vacuum forming, the above-mentioned unevenness for product design pattern can be printed on the surface of said surface skin material, and by this reason, the hand-works for it can be omitted.